Hydrocarbon cracking process

Claim 2

A process for cracking comprising contacting a hydrocarbon feed comprising at least one alkane having 2 to 20 carbon atoms per molecule under cracking conditions with H 2 S and a solid contact material comprising silica having a surface area of at least 50 m 2 /gram, wherein more H 2 S is employed than is needed for inhibiting carbon formation under said cracking conditions.

Claim 3

A process for cracking comprising contacting a hydrocarbon feed comprising at least one alkane having 2 to 20 carbon atoms per molecule under cracking conditions with H 2 S and a solid contact material comprising silica having a surface area of at least 50 m 2 /gram, wherein the amount of H 2 S is greater than that needed to substantially inactivate the carbon forming activity of any materials present which in the absence of the H 2 S would catalyze carbon formation under said cracking conditions.

Claim 4

A process for cracking comprising contacting a hydrocarbon feed comprising at least one alkane having 2 to 20 carbon atoms per molecule under cracking conditions with H 2 S and a solid contact material comprising silica having a surface area of at least 50 m 2 /gram, wherein the amount of H 2 S is greater than that needed to substantially inactivate the carbon forming activity of any materials present which in the absence of the H 2 S would catalyze carbon formation under said cracking conditions.

Claim 5

A process according to claim 2 wherein said cracking is carried out at a temperature in the range of about 400° C. to about 900° C.

Claim 6

A process according to claim 3 wherein said cracking is conducted in the absence of materials that are in a form that would cause any significant amount of carbon formation if said H 2 S were not employed.

Claim 7

A process according to claim 4 wherein said refractory material comprises silica gel.

Claim 8

A process according to claim 5 wherein said silica gel has a surface area in the range of about 50 m 2 /gram to about 350 m 2 /gram.

Claim 9

A process according to claim 6 wherein said refractory material consists essentially of silica gel.

Claim 10

A process according to claim 7 wherein said hydrocarbon feedstream consists essentially of n-butane.

Claim 11

A process according to claim 7 wherein said hydrocarbon feedstream consists essentially of n-decane.

Claim 12

A process for cracking comprising contacting a feed comprising at least one alkane having 2 to 20 carbon atoms per molecule under cracking conditions with H 2 S and particles of silica gel having a surface area in the range of at least 50 m 2 /gram wherein more H 2 S is employed than is needed for inhibiting carbon formation under said cracking conditions.

Claim 13

A process for cracking comprising contacting a feed comprising at least one alkane having 2 to 20 carbon atoms per molecule under cracking conditions with H 2 S and particles of silica gel having a surface area in the range of at least 50 m 2 /gram wherein more H 2 S is employed than is needed for inhibiting carbon formation under said cracking conditions.

Claim 14

A process according to claim 10 wherein said feed consists essentially of one or more alkanes each having 2 to 12 carbon atoms per molecule.

Claim 15

A process according to claim 11 wherein the major portion of the alkane in said feed is n-butane.

Claim 16

A process according to claim 12 wherein propylene is separated from the effluent of the cracking reaction.

Claim 17

A process according to claim 11 wherein the major portion of the alkane in said feed is n-decane.

Claim 18

A process according to claim 11 wherein said alkanes of said feed are selected from the group consisting of ethane, propane, isobutane, and n-decane.

Claim 19

A process according to claim 11 wherein said silica gel has a surface area in the range of about 80 to about 350 m 2 /gram.

Claim 20

A process according to claim 16 wherein the H 2 S is employed in an amount in the range of about 1 to about 3 mole percent based on the total moles of alkane in said feed.

Claim 21

A process for cracking comprising contacting a hydrocarbon feed comprising at least one alkane having 2 to 20 carbon atoms per molecule under cracking conditions with H 2 S in a reaction zone containing a solid contact material comprising silica having a surface area of at least 50 m 2 /gram, wherein said contact material has been contacted in said reaction zone with enough H 2 S that additional H 2 S does not provide any additional significant decrease in the level of carbon formation under the cracking conditions.

Claim 22

A process for cracking comprising contacting a hydrocarbon feed comprising at least one alkane having 2 to 20 carbon atoms per molecule under cracking conditions with H 2 S in a reaction zone containing a solid contact material comprising silica having a surface area of at least 50 m 2 /gram, wherein said contact material has been contacted in said reaction zone with enough H 2 S that additional H 2 S does not provide any additional significant decrease in the level of carbon formation under the cracking conditions.

Claim 23

A process according to claim 18 wherein said feed consists essentially of n-butane and the product comprises propylene.

Claim 24

A process according to claim 19 wherein the H 2 S is employed in an amount in the range of 0.1 to 10 mole % based on the moles of n-butane.

Claim 25

A process according to claim 20 carried out at a temperature in the range of 500° C. to 800° C.

Claim 26

A process according to claim 21 wherein said solid contact material consists essentially of silica.

Claim 27

A process according to claim 22 wherein said solid contact material consists essentially of silica having a surface area in the range of 80 to 350 m 2 /gram.

Claim 28

A process according to claim 23 wherein propylene is separated from the effluent of the cracking reaction.